doubraya



(No Model.) 2 Sheets-She-et 1.

SJDO-UBRAV'A.

ELECTRIC ARC LIGHT.

No. 366,938.. Patented July 19, 1887.

N. PEIERS. ym-mo ma, Washmgmn. ac.

S. DOUBRAVA. 'ELEGTRIC ARC LIGHT.

No. 366,938. Paten tedJuIy'IQ, 1887.

(No Model.) 2 Sheets-Sheet 2.

W A 2 fm 170 lib Alva UNITED STATES PATENT OFFICE.

STEFAN DOUBRAVA, OF PRAGUE, BOl-IEMIA, AUSTRIA-HUNGARY.

ELECTRIC-ARC LIGHT.

SPECIFICATION forming part of Letters Patent No. 366,938, dated July 19, 1887.

Application filed August Q5, 1886. Serial No. QlLSCQ. (No model.)

To all whom it may concern:

Be it known that I, STEFAN DOUBRAVA, a citizen of Austria-Hungary, and a resident of Prague, in Bohemia, Austria-Hungary, have invented certain new and usefullmprovements in RegulatorsforElectric-Arc Lights, of which the following is a specification.

My invention relates to an improvement in arc-lamp regulators; and it consists in regulating its are by a movable solenoid or solenoids movably suspended in the field of a fixed magnet, the solenoids being in an electric bridge between a resistance and are lamp on one side of a split circuit and two resistances on the other side.

The particular features which I regard as novel will be definitely indicated in the claims.

The regulation of this regulator is perfectly independent of the attraction, and only requires a system of electro-magnets and solenoids in which by reversing the current in one-part thereof the direction of the movement is also reversed.

The following will explain the above assertions.

A, Figure l, is an electromagnet provided with elongated poles S and N; On these poles two solenoids, B O, are moving free, connected with each other by a cord running over the pulleys a I). If a current is sent through these solenoids in such direction that B at the top has the same pole as A, but 0 has the opposite, then there will be a movement of the solenoids in the direction of the arrow. The force which moves the solenoids is different in different positions of the latter, and this difference has its cause in the fact that the forces of the solenoids are summed together in certain positions, but partly compensate each other in others. If in a diagram the distances of the solenoid B, for instance, from the electro-magnet A are represented as abscisses and the forces acting upon the solenoids as ordinates, the curve A shown in the diagram Fig. 2 would result. If the direction of the current in the solenoids 13 C is reversed while it remains the samejn the electro-magnet A, then the direction of the movement is also reversed. From this it is easy to see that it is possible to combine such systems of electro-magnets and solenoids in which in large circuits by reversing the current in a part of the system the direction of the movement is also reversed.

The following is to explain that with a correct reversion of the current such system can be used for the regulating of are lights, and that such reversion of the current can be produced automatically without intricate mechanism and without interrupting the current bya combination of the arc with proper re sistances, and this is the principal point of the present invention.

First, it is to be shown how the system can be employed for the regulating of the are light. Supposing the two solenoids B and C, Fig. 3, carry carbon-holders m a with carbons, 0 p touching each other, and the current is sent through the lam p,the solenoids must have such poles toward the electro-magnet that a movement in the direction of arrow 1 results. The carbons are thus separated and the are produced. At the moment when the normal are is reached the current in the solenoids ceases through the forces compensating each other, and the movement stops. If the sys tem is properly adjusted, the carbons will remain in this position until they burn away and the are becomes too long, in which case the current is to flow through the solenoids in the reverse direction, resulting in a movement in the direction of arrows 2, and the carbons are moved toward each other until the normal arc is reached again, when the current ceases in the solenoids and the movement stops again.

For the proper operation of the lamp there are therefore three problems to solvei. (2., with the normal length of the are the current in solenoids is to be nil, then with a short are the current must flow through the solenoids in one direction and with a long arc in the other. This is effected by combining the electro-magnet, the solenoids, the are, and a rheostat of a proper resistance to a lVheatstone or Thomson-Wheatstone bridge.

Figs. 4 and 5 represent in a diagram the combination of the different parts. Fig. 4. is a combination for the simple WVheatstone bridge. The coil of the electro-magnet is divided into two, .A A, between which one end of the bridge-wire is connected, in which are ar ranged the solenoids B O. The other end of the bridge-wire is connected between the rheostatR and the are 0 p. If the resistances of A A are equal, the bridgc-wirc is' with out any current only when the resistance of the are is exactly equal to that of the rheostat. If the resistance of the are be smaller or greater than the resistance of the rheostat, then a current will pass through the bridge-wire with the solenoids in one or the other direction, and a movement will result until the resistances of the rheostat and the are are equal again, or in the same proportion as A to A, and the nor mal are is again reached. The current is introduced into the bridge system at a and I). For example, in Fig. 4, when the lamp is first put into operation the are branch of the split circuit is of lower resistance than the magnet branch. At the point A the current divides, part going by way of resistance It and part by way of A. The magnet A, being of higher resistance than the are at the moment of starting,shunts partof the current across the bridge at C and excites the solenoids. This lifts the carbons and establishes the are. Sufficient current will pass from O to B to excite the magnet A. As the carbons burn away the re sistance of the are becomes higher than that of the magnet A. The are will then shunt current across the bridge at D, thus reversing it in the solenoids and reducing the size of the are. It will thus be seen that the solenoids are moved in one direction or the other as the resistance of the are varies, and. a balance is kept up, preserving the are at a substantially fixed length. This length may be controlled in any given lamp by a proper adjustment of the rheostat It. The are is the variable element of the lamp, the others being constant, and by the fluctuations of the are the current is forced across the bridge and through the solenoids to shift the carbons closer or farther apart.

The diagram Fig. 5 only differs from the preceding in that the coil of the electromagnet is divided into four parts, A A A A.

From the foregoing it is clear that this regulating system differs materially from those depending on the direct action of the current, because all these are based on the differential principle, and the two magnetic momcntumsone produced by the primary and the other by the secondary current-- counterbalance each other when the are is of normal length. The momentums are therefore equal, but of opposite direction. In my regulating system this balance is produced by the cessation of; the current in one part of the regulating electromagnetic system when the arc is of normal length.

The system described above has, like most others, the fault that the forces of the two solenoids partly compensate each other in certain positions, whereby the regulating force is diminished. I have therefore chosen a system in which in no position of the different parts is the regulating force diminished.

The circuit in the lamp is arranged as shown in the diagram Fig. 4 or Fig. 5. The current is divided in two branches, onegoing through the rheostat and the are, the other through the electro-magnels. The bobbins are colr nected in the bridge-wire. I therefore use magnetic systems consisting of closed parallelograms or rings of soft non-magnetic iron. Fig. 6 represents a diagram of such an arrangement. The parallelogram a b 0 dis provided on two sides with fixed solenoids A B and on the other two sides with movable solenoids C D, which latter are connected by a cord, s, running over a roller, R. Through the fixed solenoids a current is sent, which converts the side a of the parallelogram into an Spole and the side 7) into an Npolc. If, now, a current is sent through the movable solenoids, producing poles, as shown in Fig. 6, these solenoids will move in the direction of the arrows. If the direction of the current be reversed in one pair of solenoids only,while it remains the same in the other, the direction of the movementof themovablc pair of solenoids will also be reversed. The carbon-holders K K are connected directly with the movable solenoids, so that they follow the movement. One pair of the solenoids is connected up with the bridge-wire of the lVheatstone bridge, while through the other pair a current of unchangeable direction is sent.

As represented in Fig. 7, instead of a parallelogram, a closed ring, F, may be used. In this case the solenoids of each pair are placed diametrically opposite each other and the movable solenoids C D are connected by an arm, II, which turns round a central axis, 0. Under the same conditions the effectis similar to that in Fig. 6.

It is not necessary that only the bobbins A and B or O and I) should be wound with wire of the same size. The bobbins A O or A I) may be wound with thin and B D or B C with thick wire, or vice versa, or each bobbin may be wound partly with thin and partly with thick wire; but the direction of the currents must always be such in the two branches that they act on the electro-magncts in the opposite direetion.

The electro-magnets may be connected in a shunt as long as they form an astatic-needle pair. If the lamp is in a parallel shunt with the rheostat, it is not necessary to use the primary current for the regulation of the lamp, as two secondary currents will do as well. Fig. 8 represents this arrangement in diagram. The bobbins A B are connected in a secondary current branching off from the rheostat at a and b. The bobbins O D are connected in a secondary current branching off from the lamp at c d. \Vhat has been said about the winding of the bobbins applies here also, and the secondary currents must also be so arranged that they act upon the electro-magnets in the opposite direction- 17. 0., the secondary current a A B b to move the carbons away from each other and c C D d to move them toward each other. The regulating may also be effected by overlappingsecondary currents, as shown in diagram in Fig 9.

I clai1n-- TIO - arc and resistance on the other side of asplit circuit, substantially as and for the purpose set forth.

3. In an arc-lamp regulator, the combination of a split circuit, a fixed electro-magnet on one side of an electric bridge connecting the two branches, said electromagnet having downwardly-extended poles, movable oppositely-wound solenoids in said bridge sliding on said poles, and a cord and pulley for supporting said solenoids, one terminal of the bridge being between the arc anda resistance, and the other terminal being between two suitable resistances, as and for the purpose set forth. 7

4. In an arclamp regulator, the combination ofa split circuit, a fixed electromagnet in onebranch thereof, provided with a core in a complete magnetic circuit, and a movable solenoid sliding on said core, said solenoid being in an electric bridge between suitable resistances on the fixed magnet side and the arc and a resistance on the other side, as set forth.

5. In an arc lamp regulator, a fixed electromagnet in a shunt around a resistance, extended poles on said magnet, movable solenoids on said poles, said solenoids carrying the lamp-carbon and being in'a shunt around the are, as and for the purpose set forth.

G. In an arc-lamp regulator, asplit circuit, the are and a resistance on one side, a fixed electro'magn'et on the other side, an electric bridge extending from a point between the magnetterminals to a point between the arc and resistance, and a movable solenoid in said bridge, said solenoid carrying a carbon and locatedwithin the field of the fixed magnet, as s'et'forth.

7. In an arc-lamp regulator, a split circuit, the arc and aresistance on one side, a fixed electro-magnet on the other side, an electric bridge extending from a point between the magnet-terminals to apoint between the arc and resistance, said bridge including additionai coils around the fixed magnet, and a movable solenoid in said bridge, said solenoid carrying a carbon and located within the field of the fixed magnet, as set forth.

In testimony whereof I havehereunto set my hand in the presence of the two subscribing witnesses.

STEFAN DOUBRAVA.

Wit n esses VVENZEL HERVERT, 'ADOLF FIROHY. 

